SAN FRANCISCO, April 28 (Reuters) - Rescue crews were searching on Monday for the pilot of a vintage single-engine airplane that went missing after colliding with another plane over the San Francisco Bay while returning from an air show, officials said.

The vintage Cessna 210 collided with a World War Two-era Hawker Sea Fury TMK 20 late on Sunday afternoon and dropped into the waters off of the city of Richmond, just northeast of San Francisco, U.S. Coast Guard spokesman Adam Stanton said.

After the midair crash, the Sea Fury - flown by a husband and wife - was able to safely land at the Eagles Nest Airport, about 100 miles to the east in Amador County, Amador County Undersheriff Jim Wegner said.

Both of the planes were headed to the airport after participating in the Pacific Coast Dream Machines air show in Half Moon Bay, a coastal city a half-hour drive south of San Francisco.

"Everyone associated with the Pacific Coast Dream Machines Show is terribly saddened by this news and we hope and pray the missing plane and survivors are found," the organization said in a statement posted online.

Organizers of the event, which features vintage planes, cars and an air show, said only one person was expected to have been on the downed plane.

No Cessna plane wreckage or crash victims had been located by Coast Guard boats or helicopters by Monday, after crews searched the area overnight, Stanton said. It was not immediately clear what had caused the incident, he said.

Witnesses told the San Francisco Chronicle that the Cessna had "spiraled out of control" and crashed into the bay after the collision.

The National Transportation Safety Board and the Federal Aviation Administration is investigating the incident. The agencies were not immediately available for comment on Monday. (Editing by Cynthia Johnston and James Dalgleish)